Chaser and chaser holding means



March 10, 1942. w. J. HOGG CHASER AND CHASER HOLDING MEANS Filed Oct. 24, 1939 INVENTYOR. WCUL'QJTL [17 (195/ Patented Mar. 10, 1942 warren STATES N T FF 1 CE.

National Acme Company,

corporationof Ohio Cleveland, Ohio, a

Application October 24, 1939, Serial No. 300,931

19 Claims.

This invention relates to chasersand chaser supporting means, the object of theinvention be ing to provide an improved chaser and chaser clamping means, the latter an improvement upon that shown and described in my'copending ap-- plication, Serial Number 295,721, fi1edSeptember 20, 1939, the present invention having primarily to do with the chaser and the locking means for securing it in position in its carrier.

A further object of the inventionis the provision of an improved reversible chaser whereby either end of the chaser maybe used for starting the cut, and improved locking meansifonsecuring this reversible chaser in its carrier, and ,which issimple in construction and eificientin use.

In vthe drawing accompanying .and'forming a part of this specification, 11,15 aview illustrating the chaser supporting block and its carrier withthe chasersecured-inthe latter.

Fig. 2 is a viewtaken atright angles to Fig. :1.-

Fig. 3 a sectional view taken on line 3-3 of Fig. 1, and

Fig. 4 is asectional view taken on the line ll cf Fig. 2, illustrating the position of :the parts when first assembled -and before the clamping screw is set to force thechaser tightly intoits slot.

Similar characters of reference indicate corresponding parts in the several views.

Before explaining in detail the present improvement and mode of operation thereof, I desire it understood that the invention is not limited to the details of .construction and arrangement of parts illustrated in the accompanying drawing since the invention is-capable of other embodiments, and that'the phraseology employed'is-for'the purpose of description and not of limitation.

Since the chaser block and its carrier and-the advantages thereof are described in detailin my copending application heretofore referred to wherein a series of rectangular or tangential chaser blades, as they are commonly called, are independently mounted, each on its sliding chaser block carried in the-chaser carrier or die head for shiftable movement toward and from the work to be threaded and whereby'the clearance angle of each chaser blade may be independently adjusted, these .parts will be but generally designated.

The chasersupporting block l receives achaser carrier 2 having a machined slot 3 for the reception of the chaser A retained therein by a locking screw'5 and nut 6. The slot '3 or chaser supporting seat'o'f'this chaser carrier-or supporting member is, as shown in Fig. 1, angularly located with the result'that the chaser is alwayspositioned to give the proper clearance, rake or relief-since, as is well known, the chasers always out ahead of the center thereof without-the necessity-of grinding the chaser for this'purpose. Consequently, the chaser teeth do not have to be cut or ground on an angle to give-the necessary clearance or rake but-are ground straight across and are, therefore, at right angles to both side walls of the chaser blade; that is, the ends of the cutting teeth at one side are no higher than those at the other, as distinguished from the usual construction of chasers which are ground obliquely to theside walls of the chaser blades so that onesideqof the :blade, that'is, the ends of the teeth at one side are higher-than the heel ends of the teeth at the other sideof the blade to give the proper angularity of 'the teeth across the cutting face of the blade and provide the proper -relief,.clearance;or rake as shown, for instance, in my prior application, see Fig. 4, where the chaser bladeis notreversible. Consequently, the chasers in thepresent instance may be reversed and still have the same clearance, angle, rake 'or relief without any regrinding thereof. Thus, this improved chaser, while havingits teeth straight across the cutting face; is stillreversible without the necessity of cutting or,grinding the teeth on an angle to give the necessaryangularity thereof in the first instance or on the reversal thereof.

The chaser 4 is slightly hollowed or concaved at each side whereby the ends of the cutting teeth project slightly beyond these concaved sides, thus forming an efi'icient cutter is provided on both sides thereof with angle slots 1, 'eachcomprising a tapered side wall 8 and=termihating in an abrupt wall 9 whereby the-chaser, both ends'of which are formed alike, may be "reversed in its slot so that either end of this -'rectangularchaser maybe used to start the cut,

the chaser being face-ground on both sides. Thus. this chaser has a row of cutting teeth along one face formed to cutthe same thread from either end when reversed and rotated in the same direction.

The clamping screw 5 cooperating with this angle slot formation of the chaser is provided with a head In located in an opening 2' in the carrier 2 and *the head [0 is of such formation that it will accurately fit into either angle slot of the 'reversible chaser so as to engage the tapered inner wall 8. of this chaser slot andfor this purpose, the head has an overhanging tapered engaging portion I I and the construction is such that when the clamping screw 5 is tightened by its nut 6, it not only forces the chaser against the rear side wall I2 of the chaser carrying slot but also against the bottom wall I3 of that slot, thereby securing the chaser in the proper position and insuring a uniform cutting action of all four chasers of the die.

The head of the clamping screw is provided with a slot M to receive a pin I5 of the carrier 2 which holds the clamping screw 5 in proper position.

As the other parts of the carrier and supporting block, together with the adjusting means of the carrier and the advantages thereof, are similar to those shown and described in my copending application, a detailed description thereof is deemed unnecessary herein.

It is to be understood that, by describing in detail herein any particular form, structure or arrangement, it is not intended to limit the invention beyond the terms of the several claims or the requirements of the prior art.

Having thus explained the nature of my said invention and described a way of constructing and using the same, although without attempting to set forth all of the forms in which it may be made, or all of the modes of its use, I claim:

1. The combination with a chaser block and a chaser carrier supported thereby having a chaser receiving slot, of a rectangular chaser reversible in its slot and having a row of cutting teeth along one face and face ground on both sides to cut from either side edge, said chaser having angle slots in its opposite side faces, and a clamping device carried by the carrier and having a head adapted to cooperate with either of the angle slots of the chaser for clamping the chaser in position.

2. The combination with a chaser block and a chaser carrier supported thereby having a chaser receiving slot, of a reversible rectangular chaser having a single set of cutting teeth adapted to cut from either end and having angle slots in its opposite side faces, and a clamping device carried by the carrier and having a head adapted to cooperate with either of the angle slots of the chaser for clamping the chaser in position, the angle slots of the chaser and the head of the clamping device having such construction that they will cooperate to cause the chaser to engage the side and bottom walls of its slot.

3. The combination with a chaser block and a chaser carrier supported thereby having a chaser receiving slot, of a reversible rectangular chaser having a single set of cutting teeth adapted to cut from either end and having angle slots in its opposite side faces, and a clamping device carried by the carrier and having a head adapted to cooperate with either of the angle slots of the chaser for clamping the chaser in position, the angle slots of the chaser and the head of the clamping device having a tapered construction so that they will cooperate to cause the chaser to engage the side and bottom walls of its slot.

4. The combination with a chaser block and a chaser carrier adjustably supported thereby having a chaser receiving slot, of a rectangular chaser reversible in its slot and having a row of cutting teeth along one face and face ground on both sides to cut from either side edge, said chaser having angle slots in its opposite side faces, and a clamping device carried by the can rier and having a head adapted to cooperate with either of the angle slots of the chaser for clamping the chaser in position.

5. A reversible chaser having its teeth out or ground straight across its cutting face and at right angles to both sides of the chaser both sides being ground alike so that, on the reversal thereof, it can cut from either end and preserve the proper clearance, rake or relief when the chaser is set at an angle in its supporting memher.

6. The chaser of claim 5 having angle slots in both sides thereof.

7. The chaser of claim 5 having angle slots in both sides thereof, each comprising a tapered wall terminating in an abrupt wall.

8. The chaser of claim 5 having angle slots in both sides thereof, and means cooperating with the angle slots for clamping the chaser in position.

9. The chaser of claim 5 having angle slots in both sides thereof, each comprising a tapered wall terminating in an abrupt wall, and means cooperating with the angle slot for clamping said chaser in position.

10. The chaser of claim 5 in which the chaser is hollow ground at both sides thereof adjacent to the teeth.

11. The combination of a chaser supporting member having a chaser supporting seat angularly inclined relative to the radius from the axis of rotation and a chaser carried by said angular seat.

12. The structure of claim 11 in which the chaser carried by said angularly inclined seat and having a row of teeth is reversible end for end of its row of teeth relative to said seat.

13. The combination of a chaser supporting member having an angularly located chaser supporting seat and a chaser carried by said angular seat and having its teeth out or ground straight across its cutting face and at right angles to both sides of the chaser and reversible end for end of the row of teeth whereby, on the reversal thereof, it is adapted to cut from either end while preserving the proper clearance, rake or relief by reason of the angularity of said seat.

14. The structure of claim 13 in which the chaser is hollow ground at both sides adjacent to its cutting teeth.

15. The combination with a chaser block and a chaser carrier adjustably supported thereby and having an angularly located chaser supporting seat, of a rectangular chaser reversible end for end of its row of teeth relative to said angular seat whereby, by reason of the angular location of the seat, the chaser may be reversed so as to have the proper clearance without the necessity of cutting the thread at an angle to relieve the chaser.

16. The structure of claim 15 in which the teeth of the chaser are cut or ground straight across its cutting face and at right angles to both sides of the chaser whereby the heel and starting end of the teeth are at the same height.

17. A chaser comprising a detachable and reversible rectangular blade having all along one face from end to end thereof a continuous series of parallel cutting teeth and face ground on both sides to provide cutting edges on opposite sides of the row of teeth, said chaser having both ends of the row of teeth formed to cut the same thread, thereby providing a chaser reversible end for end of the row of teeth to cut from either side of the chaser when rotated in the same direction and whereby the chaser, by reason of its detachability, may be adjusted independently of its companion chasers to provide for the proper clearance angle of the chaser.

8. A rectangular chaser having all along one face from end to end thereof a continuous series of parallel cutting teeth and face ground on both sides to provide cutting edges on opposite sides of the row of teeth, said chaser having both ends of the row of teeth formed to provide a chaser reversible end for end of the row of teeth to cut from either side edge of the chaser, the chaser having angle slots in both sides thereof, each comprising a tapered inner wall terminating in abrupt wall, and means cooperating with an angle slot forclamping said chaser in position and having a tapered face cooperating with the tapered face of the angle slot of the chaser.

19. A rectangular chaser having all along one face from end to end thereof a continuous series of parallel cutting teeth and face ground on both sides to provide cutting edges on opposite sides of the row of teeth, said chaser having both ends of the row of teeth formed to provide a chaser reversible end for end of the row of teeth to cut from either side edge of the chaser, and having angle slots in both sides thereof, each comprising a tapered inner wall terminating in an abrupt wall and means cooperating with an angle slot and having an overhanging tapered face corresponding to the tapered face of the chaser angle slot for clamping the chaser in position.

WILLIAM J. HOGG. 

